Households whose abilities differ — with age, with disability, with the changing membership of a life-stage — make demands on their housing that shift across a building’s long life. Most will be housed by stock that already stands, so the binding question is how much change an existing dwelling can absorb. That capacity is limited, on our reading, as much by a dwelling’s representational infrastructure — its drawings, schedules, certificates, and the regulatory texts they answer to — as by its physical fabric: a change meant to stay local repeatedly forces global re-checking across every commitment that holds the dwelling together. Keeping a local change local — a problem of representational governance — is what this thesis treats as a design-science problem and answers with a modular architecture for the dwelling.

The response transposes two lineages onto housing. From the study of complex systems — Simon, Parnas, Baldwin and Clark — it takes the principle that change stays tractable when interdependence is bounded by stable interfaces that publish what others may rely on and hide what lies within; from Open Building, the layered dwelling whose long-life support carries a renewable short-life infill. Joining them yields the thesis’s central artefact, a Governed Kernel Architecture: a governed kernel — a small set of design rules, nine functional space-types over a stratified vocabulary of seven primitives and seven composites, a variant-inheritance rule, and explicit interface contracts — around which life-cycle variation is absorbed in a bounded governed instance library. The kernel is governed rather than frozen: fixed for any given configuration, yet revisable through a rule-bound, versioned path. The architecture is instantiated as a coordinated artefact suite: a design theory; a schema that renders regulatory prose queryable; the module system that houses the kernel; a planimetric notation that can be written and read back without loss of meaning; a generation-and-documentation pipeline; and an empirical substrate of 745 Australian floor plans. Specialist Disability Accommodation under Australia’s National Disability Insurance Scheme serves as the proving ground, not the subject, because it concentrates the difficulty into one auditable instrument.

The decisive test sits at a single fork: one four-bedroom dwelling branches two ways — the original occupants ageing in place, or a higher-support refurbishment with an attached secondary dwelling — and both, on our reading, are absorbed without the governed kernel moving. A representation that travels intact between actors, and one that confines the effects of a local change, appear well supported; governed variation under shared rules holds at moderate confidence within the single branch examined; faithful replay of authoring acts, and net benefit across a dwelling’s life, remain only partly established. Wider rater studies, further trajectories, other building stocks and regulatory regimes, and a production implementation would extend the warrant.

Keywords: modular architecture and design rules; governed kernel; housing adaptation; representational governance; Open Building; planimetric notation; design science research.